Self-adjusting detachable fuse clip for cartridges



July 15, 1969 F. SLAWINSKI 3,455,242

SELF-ADJUSTING DETACHABLE FUSE CLIP FOR CARTRIDGES Filed Aug. 24, 1967 20 FIG. 2-

FIG.i

INVENTOR. Frank E. Slowinski nited States ABSTRACT OF THE DISCLOSURE A self-adjusting detachable fuse clip is provided which may be opened and slipped around various circumferences of blasting cartridges for supporting a detonating cord adjacent thereto. In one embodiment, finger gripping members are provided to aid the opening of the clip.

This invention relates to a device for effectively holding a detonating cord adjacent to a blasting cartridge. More particularly, the present invention provides a selfadjusting detachable fuse clip which may be readily opened and slipped around various circumferences of blasting cartridges for supporting a detonating cord adjacent thereto.

A need has existed in the explosives industry for a simple but eflicient means to support a detonating cord adjacent to a blasting cartridge. Various means such as the use of tape, string and the like have been customarily used to hold a detonating cord adjacent to a blasting cartridge but these means have proven time consuming due to the manipulation involved. Devices such as wire clips have been proposed but these have proven, in some instances, to be both dangerous and inefficient.

It has now been found that by using the device of the present invention, a simple, inexpensive, and eflicient means is provided for holding a detonating cord adjacent to a blasting cartridge. In addition, the present invention provides a device having great versatility in that it may self-adjust to fit various circumferences of blasting cartridges.

Generally stated, the present invention provides a fuse clip formed as one piece of a plastic material and having a longitudinally disposed detonating cord receiving, U-shaped channel member with legs of said channel member forming two bowed-continuous leg surfaces for surrounding a blasting cartridge. In one embodiment, the bowed leg surfaces overlap in an area substantially opposite the channel portion of said U-shaped member when in normal position. In another embodiment of the present invention, finger gripping means are provided on each bowed leg surface for opening the leg surfaces when slipping same around the circumference of a blasting cartridge.

Referring to the drawings wherein like reference numerals refer to like elements through the several views:

FIG. 1 is an end elevation of the fuse clip of the present invention;

FIG. 2 is a front elevation of the fuse clip of FIG. 1;

FIG. 3 is an end elevation of an embodiment fuse clip having finger gripping members to aid the opening of the clip;

FIG. 4 is a front elevation of the fuse clip of FIG. 1 illustrated in place about the circumference of a blasting cartridge and supporting a detonating cord adjacent thereto; and

FIG. 5 is an end elevation of the fuse clip, blasting cartridge, and detonating cord of FIG. 4.

FIGS. 1 and 2 illustrate fuse clip having left bowed leg surface 12 and right bowed leg surface 14 which overlap at area 15 when in normal position as shown. Alternatively, the fuse clip may be formed without the overlap although the elimination of the overlap may limit the area of contact about larger diameters of blasting cartridges.

The bowed leg surfaces 12 and 14 form left channel leg 16 and right channel leg 18, respectively, and terminate to form U-shaped channel member 20. U-shaped channel member 20 is constructed to receive a detonating cord and is of heavier wall thickness than the bowed leg surfaces for both strength and elastic purposes.

An embodiment fuse clip 22 is illustrated in FIG. 3. Fuse clip 22 is similar to fuse clip 10 in that it is provided with left bowed leg surface 24, right bowed leg surface 26, overlap area 28, left channel leg 34, right channel 36, and U-shaped detonating cord receiving channel 38. In addition, finger gripping members 30 and 32 are provided on left bowed leg surface 24 and right bowed leg surface 26, respectively and preferably near the overlap area 28 for better leverage in opening the leg surfaces during placement of the fuse clip about the circumference of a blasting cartridge. These finger gripping members 30 and 32 may be formed along the entire length of fuse clip 22 or may be formed along a segment thereof. Variations in the construction and placement of these finger gripping members are also possible.

FIGS. 4 and 5 illustrate fuse clip 10 in place about the circumference of blasting cartridge 40 and supporting detonating cord 42 adjacent thereto. Detonating cord 42 may extend to include various additional blasting cartridges, not shown, as part of an explosive train.

The fuse clip of the present invention may be formed as an extruded plastic tube having the U-shaped channel at one side with the bowed leg surfaces united opposite thereto. The extruded plastic tube may then be cut to a convenient length and split or out along the length in the area of the overlapping bowed leg surfaces. Alternatively, the extruded plastic tube may be split or cut along the length in the area of the overlapping bowed leg surfaces and then cut to a convenient length, as desired. It is generally found that suflicient stresses are present in the extruded clip such that when cut along the length, overlapping of the bowed legs results.

The fuse clip of the present invention may be readily manufactured by extruding any of a relatively wide variety of plastics which are neither brittle nor extremely flexible while retaining moderate toughness and strength. Plastic materials which are useful include polyethylene, polypropylene, polyvinyl chloride, polyvinyl dichloride, polystyrene, nylon; copolymers such as acrylonitrilebutadiene-styrene; and the like. Various other plastic materials may be used as desired provided they possess sufficient strength without being brittle or extremely flexible.

The fuse clip body may be spread or opened by flexing the area roughly diametrically opposite the overlapping legs defined by the U-shaped channel member. Due to the resilience or elasticity of the plastic material, the overlapping legs tend to resist opening and thus provide a selfadjusting feature for surrounding the circumference of a blasting cartridge.

The cross-sectional dimension of the present fuse clip ma be varied over considerable ranges in order to accommodate various diameters of both blasting cartridges and detonating cords.

The thickness of the wall of the fuse clip for the bowed legs is also subject to wide variation depending upon the over-all size of the fuse clip and any secondary reasons which will be influenced in use. However, a thickness of about 25 to about 55 mils wall thickness is typical.

The thickness of the wall of the U-shaped channel member of the present fuse clip is also subject to wide variation also depending upon the over-all size of the fuse p. However, a thickness of about 45 to about 85 mils annel wall thickness is typical. It is also desirable for 'ength and elastic reasons to retain at least a 15 mil icker wall for the channel member than for the bowed g members.

The length of the present fuse clip may be varied as sired with a typical sufiicient length being about 1 to out 5 inches.

Other variations and modifications may be made in,

r example, the size, and proportions of the present fuse .p without departing from the scope of the present inntion.

What is claimed is:

1. A plastic fuse clip for a blasting cartridge comising:

(a) a means for holding a detonating cord, said means comprising a U-shaped surface adapted to be juxtaposed longitudinally to said cartridge, the open portion of said surface adapted to face said cartridge; and

(b) a means for 'clasping said cartridge, said means comprising resilient bowed surfaces outwardly projecting from each side of said U-shaped surface.

2. The plastic fuse clip of claim 1 wherein the two Med-continuous leg surfaces overlap when in normal asition in an area substantially opposite the channel por- )II of said U-shaped member.

References Cited UNITED STATES PATENTS 862,878 8/1907 Brewer 102-24 2,361,622 10/1944 Goulet 102-24 2,423,255 7/ 1947 Rolfes 10227 2,779,280 1/ 1957 Strange 10227 3,205,818 9/1965 Coulson 102-27 FOREIGN PATENTS 334,511 3/ 1921 Germany.

733,254 7/1932 France.

VERLIN R. PENDEGRASS, Primary Examiner 

